Yaaser Q. Almulaiky

Purification and characterization of α-Amylase from Miswak Salvadora persica

BackgroundThe miswak (Salvadora persica) is a natural toothbrush. It is well known that very little information has been reported on enzymes in miswak as medicinal plant. Recently, we study peroxidase in miswak. In the present study, the main goal of this work is to purify and characterize α-amylase from miswak. The second goal is to study the storage stability of α-amylase in toothpaste.MethodThe purification method included chromatographaphy of miswak α-amylase on DEAE-Sepharose column and Sephacryl S-200 column. Molecular weight was determined by gel filtration and SDS-PAGE.ResultsFive α-amylases A1, A4a, A4b, A5a and A5b from miswak were purified and they had molecular weights of 14, 74, 16, 30 and 20 kDa, respectively. α-Amylases had optimum pH from 6 to 8. Affinity of the substrates toward all enzymes was studied. Miswak α-amylases A1, A4a, A4b, A5a and A5b had Km values for starch and glycogen of 3.7, 3.7, 7.1, 0.52, 4.3 mg/ml and 5.95, 5.9 4.16, 6.3, 6.49 mg/ml, respectively. The optimum temperature for five enzymes ranged 40°C- 60°C. Miswak α-amylases were stable up to 40°C- 60°C after incubation for 30 min. Ca+2 activated all the miswak α-amylases, while Ni2+, Co+2 and Zn+2 activated or inhibited some of these enzymes. The metal chelators, EDTA, sodium citrate and sodium oxalate had inhibitory effects on miswak α-amylases. PMSF, p-HMB, DTNB and 1,10 phenanthroline caused inhibitory effect on α-amylases. The analysis of hydrolytic products after starch hydrolysis by miswak α-amylases on paper chromatography revealed that glucose, maltose, maltotriose and oligosaccharide were the major products. Crude miswak α-amylase in the toothpaste retained 55% of its original activity after 10 months of storage at room temperature.ConclusionsFrom these findings, α-amylases from miswak can be considered as beneficial enzymes for pharmaceuticals. Therefore, we study the storage stability of the crude α-amylase of miswak, which contained the five α-amylases, in toothpaste. The enzyme in the toothpaste retained 55% of its original activity after 10 months of storage at room temperature.

In vivo evaluation of hypolipidemic and antioxidative effect of ‘Ajwa’ (Phoenix dactylifera L.) date seed-extract in high-fat diet-induced hyperlipidemic rat model

In the present study, we investigated the hypolipidemic and hepatoprotective potential of the commercially available crushed Ajwa date seed-extract on the toxicity caused by the atorvastatin in high-fat diet (HFD)-induced hyperlipidemic rats. Male albino rats were divided into two main groups, Group I (normal control) and Group II (HFD); Group II was further divided into four subgroups: Group IIa (HFD control), Group IIb (Atorvastatin: A10)-6 rats were administered with 10 mg/kg atorvastatin daily for 30 days, Group IIc (Ajwa seed extract: AJ)-6 rats were given 1000 mg/kg Ajwa seed extract daily for 30 days, Group IId (AJ + A10)-6 rats were given Ajwa seed extract 1000 mg/kg and Atorvastatin 10 mg/kg daily for 30 days. The data obtained suggested that Ajwa seed extract lowered the serum cholesterol level in HFD rats and demonstrated the hepatoprotective effect in combination with atorvastatin by reducing the levels of ALT and AST. In conclusion, it protected the tissues from the detrimental effects of hyperglycemia and enhanced antioxidant activity. Furthermore, the dose-limiting toxicity of atorvastatin may be reduced if the Ajwa seed extract is incorporated in the current treatment regimens to treat hyperlipidemia in hypercholesteremic individuals.

Investigation of antioxidant and detoxifying capacities of some date cultivars (Phoenix dactylifera L.) irrigated with sewage water

The objective of the study was to compare the effect of irrigation by municipal water (MW) and sewage water (SW) on antioxidant and detoxifying capacities of some commercial Saudi date cultivars, Agwa, Anbr and Safawi (Phoenix dactylifera L.). Higher amounts of phenolic and flavonoid were detected in dateSW compared with dateMW. The levels of accumulation of heavy metals in dateSW were higher than those of dateMW. The phenolic extracts of dateSW exhibited higher antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and the formation of phosphomolybdenum complex tests than those detected in dateMW. In the same manner, the activities of peroxidase, polyphenoloxidase and glutathione-S-transferase of dateSW were higher than those exhibited in dateMW. The higher levels of all these examined parameters, induced by sewage wastewater contaminants, may be contribute to protecting dateSW from oxidative and toxicity stresses.

Immobilization of Trichoderma harzianum α-amylase on PPyAgNp/Fe3O4-nanocomposite: chemical and physical properties

Abstract In this study, a new support has been developed by immobilization of α-amylase onto modified magnetic Fe3O4-nanoparticles. The characterization of soluble and immobilized α-amylases with regards to kinetic parameters, pH, thermal stability and reusability was studied. The effect of polypyrrole/silver nanocomposite (PPyAgNp) percentage on weight of Fe3O4 and pH on the immobilization of α-amylase was studied. The highest immobilization efficiency (75%) was detected at 10% PPyAgNp/Fe3O4-nanocomposite and pH 7.0. Immobilization of α-amylase on PPyAgNp/Fe3O4-nanocomposite was characterized by FT-IR spectroscopy and scanning electron microscopy. The reusability of the immobilized enzyme activity was 80% of its initial activity after 10 reuses. The immobilized enzyme was more stable towards pH, temperature and metal ions compared with soluble enzyme. The kinetic study appeared higher affinity of immobilized enzyme (Km 2.5 mg starch) compared with soluble enzyme (Km 3.5 mg starch). In conclusion, the immobilization of α-amylase on PPyAgNp/Fe3O4-nanocomposite could successfully be used in industrial and medical applications.

Facile Immobilization of Enzyme via Co-Electrospinning: A Simple Method for Enhancing Enzyme Reusability and Monitoring an Activity-Based Organic Semiconductor

The stability, reusability, and monitoring of enzyme activity have been investigated to improve their efficiency for successful utilization in a broad range of industrial and medical applications. Herein, we present a simple method for fabricating an electrospun fiber/enzyme scaffold via co-electrospinning. The characterization of soluble and immobilized α-amylases with regard to pH, thermal stability, and reusability were studied. An organic light emitting material tris(8-hydroxyquinoline)aluminum was incorporated to monitor the enzyme activity for several reuses.

Heavy Metal Accumulation is Associated with Molecular and Pathological Perturbations in Liver of Variola louti from the Jeddah Coast of Red Sea

Large amounts of waste water are discharged daily from the Jeddah Metropolitan Area into the Red Sea. Sewage draining into the Red Sea causes widespread chemical pollution that is toxic to aquatic ecosystems. The objective of this study was to investigate the extent of pollution and assess the presence of heavy metals in fish tissue and study their association with biological and biochemical alterations. The average concentrations of heavy metals found in hepatic tissues of Variola louti fish from the polluted area, namely Cd, Cr, Cu, Fe and Zn, were 1.74, 9.69, 47.48, 4020.01 and 229.47 µg/g liver, respectively, that were significantly higher than that of samples taken from reference area (0.24, 1.98, 20.12, 721.93, 129.21 µg/g liver, respectively). The fold change of heavy metals in fish from the polluted area with respect of that of the reference area followed the order Cd > Fe > Cr > Cu > Zn. Analysis of nuclear DNA revealed that hepatic tissues of fish samples from the polluted area showed a significant increase in apoptotic cells as detected by flow cytometry and formation DNA-ladder. In addition, hepatic sections from polluted area fishes showed more fibrotic changes and collagen deposition by hematoxylin-eosin staining and Masson’s trichrome staining, respectively, compared to samples taken from the reference area. Moreover, the electrophoretic patterns of proteins of liver of fishes caught at the polluted area showed different patterns of proteins from that of the reference with bands at 42, 130 and 140 kDa, which is in a good agreement with the molecular weight of collagen type III. In conclusion, there were significant changes in the tissues of fishes in the polluted area at the cellular and the molecular levels that may be associated with an accumulation of heavy metals. Assessment of fishes as a sensitive biomonitor for the pollution of surface waters that may affect general health of human and wild life is conceivable.